Electroplating



Sept. 9, 1952 A. B. WILSON 2,610,145

ELECTROPLATING v Original Filed May 28, 1943 2 SHEET$-SHEET l 3maentors ABRAM B. WILSON A. B. WI LSO N ELECTROPLATING Sept. 9, 1952 2 SHEETSSHEET 2 Original Filed May 28, 1943 ABRAM B. \ifiii'gml attorney Patented Sept. 9, 1952 ELECTROPLATING Abram B. Wilson,Weirton, W. Va.,

National Steel. Corpor- Delaware assignor to ation, a corporation of.

"Original application May 28, 1943, Serial No.

488,866. Divided and this application March'z, 1949, Serial No. 79,150 i a The present invention relates to continuous electroplating of a moving strip having a con: ductive face. i I More particularly, the present invention relates to electroplating ofa protectivemetal such as tin, zinc, nickel, chromium, etc. on a metal strip, wherein anodes of the coating metal are supplied with electroplating current through a connection submerged in the electrolyte;

This application is a division of application Serial No. 488,866, now abandoned, filed May 28, 1943, by Walter W. Kompart and myself as joint inventors. I

The present invention is especially adapted for use in electroplating systems of the general type disclosed in copending application Serial No. 487,758, filed May 20, 1943, by Ernest W. Rieger and Clarence J. Klein which issued as Patent No. 2,399,254 on April 30, 1946. In elec troplating systems of this type a moving strip having a conductive face, for example, steel strip, is moved through an electroplating zone in which at least oneface of the strip i contacted with an electrolyte. Submerged under thesurface of the electrolyte and in electrolytic relation with the face of the strip are anodes of the metal to be platedon the strip. These anodesmay be arranged in any desirable man her to give a uniform coating action, but nor mally they are mov-ably supported on anode supports from at least one of which they collect electroplating current. Since the connection between these anodesan-d the support which carries the electroplating potential must be in the electrolyte, many difiiculties have been experienced in maintaining suitable electrical contacts A H An importantobject. of the present invention is the provision of an eflicien-t electrical connection between submerged soluble anodes and a source of electroplating current.

A further important object of the present invenfion is the provision of an eiiicient electrical connection between movable soluble anodes submerged in electrolyte and a source of electroplating current;

A further important object of the present invention is the provision of apparatus for electroplating moving strip including an improved anode support for supplying electroplating current to movable soluble anodes which are submerged in electrolyte. I

Other objects of the invention will becomeapparent from the followingdetailed description taken in connection with the accompanying drawings which disclose apparatus incorporating thepresent invention. j I j Figure 1 is a plan view of an electroplating cell incorporating the present invention, the strip to be plated being omitted;

' aclaim (01104-206) Figure 2 is an enlarged view in side elevation of the embodiment of the present invention shown in Figure 1; and H .Figure 3 is an enlarged view in cross section taken on Stheline 3---3 of Figure 2.

i Referring to the drawings, an electroplating celleis shownwh'ich may beer the type more specifically disclosed in Patent No. 2,399,254- ref-erred to above. Briefly, this cell embodiesa tray indicated generally at I having-a pairofpartitions II and I2 defining a pair of overflow troughs I3 and Hand an electroplating cell' I which is normally filled with an electrolyte (not shown) with which the strip to be plated makes contact. End walls It and I1 of the tray are of the same height as partitions II and I2 so that electrolyte pumped into cell I5 will overflow all the walls when the tray is level. It will be apparent that the strip can move through.

this cell with troughs I3 and M disposed on either side of the moving strip, or a pair of strips moving side by side could pass through the cell parallel to end members IB and I'|.-

Considering the strip as moving through the cell with troughs I3 and I 4 disposedon either side of the moving strip it will be apparent that cell I5 is divided by an anode guide or support indicated generally at. I8 extending transversely to the path of the strip. Member I8 includes a guide I9 which may be of wood or the like forming a pair of shoulders 20 and 2| which slidably receive the ends of anode elements 22.

A series of'anode elements 22 make up the pair of anodes indicated generally at 23 and 24. E'x-- tending parallel to member I8- are a pair of guide members 25 and 2B which support the otherends of the anode elements 22. Shoulders 20 and 2| of member I8 and the upper surfaces of guide members or anode supports 25 and 26 are inclined upwardly from the trough I 4 side of the cell sothat fresh anode elements can be periodically inserted at the lower end and eroded anode elements withdrawn at the upper end of the incline to make possible continuous replacement: of the anode.

The detailsofconstruction' of memberIB are best shown in Figures 2 and 3. A base member: 21 whichmay be formed of a metal having high" electrical'conductivity presents an extension 28.

designedto project above the surface of. the elec-', trolyte for connection with a source of electroplating current. Extension. 28 incorporates bus bar connection 29which will generallybe formed. of copper bars. Where base member 21 is not,

formed of copper, these bars may beextendedas at' 30 so as to be embedded in the metalof the extension 28. Supported on base or current carrying member 21 isIan anode contact strip 3|. A projection 32 onbase 21 forms an abutment for one end of strip 3|. Guide member I9 is positioned along strip 3| to present the shoulders or shoulder portions 20 and 2|. To hold the parts together, a plurality of bolts 33 are used and the parts drilled to give bore holes slightly 2.

tending across from side to side of thepath of the strip and the conductive'surface of the strip, and a protective coating on the surfaces of the ,base member and the carbon member exposed to the electrolyte to prevent the electrolyte from V chemically acting on the same, except the upper rial is inserted in the bore hole around bolt 33 and in the countersinks 34 and 35. Where deemed necessary, an eroded anode rest 36 may be bolted or fastened in any desirable manner to the outer end of base member 21 to receive the end of an eroded anode element ejected from the anode.

Anode contact member 3| ismolded or formed in any suitable manner to give a hard carbon surface for engagement with the anode, which surface shall be a good conductor of electricity and have good Wear resistant characteristics. Since the surface is continuous, the anodes may be moved therealong'with electrical contact being maintained.

- In order to prevent the electrolyte from attacking base member 21, a protective coating such as a rubber base paint 3! is applied to the base member. The base member is formed of metal having high electrical conductivity to better distribute the heavy electric current along the length of member 3|. Such metal is corrodible; that is, it is attacked and dissolved. This protective coating may cover all the parts of the support below the liquid level of the electrolyteexcept for the upper surfaces of shoulders ZOand 2|. Although not essential, it is an advantage to cover the sides of anode contact member. 3| with this protective coating to reduce to a minimum evolution, of gas at the carbon surface so that exposed surfaces of carbon member 3| and the base member are covered with a protective except for the upper anode supporting surface or surfaces of member 3|. Due to the conditions present, anode contact member 3| will act as an insoluble anode and there will be some evolution of gas wherever the electrolytecontacts the carbon surface. Only the upper surfaces of shoulders and 2|, essential as contact surfaces, need to be'left exposed.

;I claim:

Apparatus for continuously electroplating a moving strip of material having a conductive surface in which a tray presents an electroplating cell adapted to have the strip moveacross,

thefcell from end to end in a horizontal path with the conductive surface thereof in contact with the electrolyte in the cell comprising an anode-supporting structure in the tray below the path of the strip, the anode-supporting structure including a supporting base member of electrically conductive, corrodible metal extend-' ing across the tray and the pathof thestripand having'an upper surface'extending acrossfrom side to side of the path of thestrip, means for connecting the base member to a source of elec,-.

troplatingcurrent, .a member supported by the base member and formed of carbon resistant-to attack by the electrolyte anddisposed' below, the

path ofthe strip in the electrolyteofythe cell in;

electrical engagement with .the upper surface of the supporting base member along the length; of; the carbon member, the carbon member 'prfe-: senting an upper surface facing towardEandexsurface of the carbon member which is left exposed, and a plurality of soluble, electroplating anode elements submerged in the electrolyte and supported by the anode-supporting structure in electrolytic relationship with the conductive face of the strip, the anode elements being slidably mounted on and in direct electrical contact with the exposed upper surface of the carbon member.

2. Apparatus for continuously electroplating a movingstrip of material having a conductive surface in which a tray presents an electroplating cell adapted to have thestrip move. across the cell from end to end in a horizontal path with the conductive surface thereof in contact with the electrolyte in the cell comprising an anode-supporting structure in the traybelow the path of the strip, the anode-supporting structure including a supporting base member of electricallyconductive corrodible metal extending across the tray and the path of the strip and having an upper surface extending across and from side to side of the path of the strip, means for connecting the base member to a source of electroplating current, an elongated guidemember, a shoulder-forming portion formed of carbon resistant to attack by the electrolyte extending along each side of the guide member and being disposed below the path of'the strip in the electrolyte of the cell in electrical engagement with the upper surface of the base member along the length of the carbon portion,,.the carbon portions being supported by the base member and each presenting an upper surface facing toward and extending acrossfrom side to side of the path of the stripand the con ductive surface of the strip, and a protective coating on the surfaces of the base member and the carbon portions exposed to the electrolyte to prevent the electrolyte from chemically. acting on the same, except the upper surfaces of .the carbon portions which upper surfaces are left exposed, and twosets of soluble, electroplating anode elements submerged in the electrolyte and supported by the anode-supporting structure below the stri in electrolytic relationship with the conductive face of the strip, the ends of each set of anode elements being slidably mounted on and in direct electrical contact with an exposed upper surface of a corresponding one of the carbon portions. 1 1

- ABRAMB. WILSON.

REFERENCES CITED H g The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Date Number 

1. APPARATUS FOR CONTINUOUSLY ELECTROLPLATING A MOVING STRIP OF MATERIAL HAVING A CONDUCTIVE SURFACE IN WHICH A TRAY PRESENTS AN ELECTROPLATING CELL ADAPTED TO HAVE THE STRIP MOVE ACROSS THE CELL FROM END TO END IN A HORIZONTAL PATH WITH THE CONDUCTIVE SURFACE THEREOF IN CONTACT WITH THE ELECTROLYTE IN THE CELL COMPRISING AN ANODE-SUPPORTING STRUCTURE IN THE TRAY BELOW THE PATH OF THE STRIP, THE ANODE-SUPPORTING STRUCTURE INCLUDING A SUPPORTING BASE MEMBER OF ELECTRICALLY CONDUCTIVE, CORRODIBLE METAL EXTENDING ACROSS THE TRAY AND THE PATH OF THE STRIP AND HAVING AN UPPER SURFACE EXTENDING ACROSS FROM SIDE TO SIDE OF THE PATH OF THE STRIP, MEANS FOR CONNECTING THE BASE MEMBER TO A SOURCE OF ELECTROPLATING CURRENT, A MEMBER SUPPORTED BY THE BASE MEMBER AND FORMED OF CARBON RESISTANT TO ATTACK BY THE ELECTROLYTE AND DISPOSED BELOW THE PATH OF THE STRIP IN THE ELECTROLYTE OF THE CELL IN ELECTRICAL ENGAGEMENT WITH THE UPPER SURFACE OF 